The detonation took place at a residential property about one hour before the match was due to kick off, with three suspects detained at the scene. The area is home to a small Somali refugee population.

Per Maasho's report, government spokesman ShimelesKemal said:

They were Somali nationals and plotted to carry out a suicide attack disguised as fans on either the stadium or areas where large crowds gathered to watch the game.

Heavy police presence must have caused their nervousness and state of agitation which led to the detonation that caused their own death.

The report suggests that football shirts, explosives, grenades and firearms were discovered at the scene.

While there has been no claim of responsibility thus far, Somali Al-Shabaab rebels have promised to exact revenge on Ethiopia for sending troops into Somalia to fight Al-Qaeda militants, Maasho reports.

Just last month, following an Al-Shabaab siege on a shopping mall in Kenya, Ethiopia's opposition group Medrek warned that the country could face "large-scale attacks" from Somali rebels, per the Sudan Tribune.

It is not the first time that a sports event has been a target for terrorists, with this year's Boston Marathon and the Munich Olympic Games two notable past instances of sports being at the centre of such an incident.

Football matches, also, have been targeted. Nine people were injured in 2002 when Spanish separatist group Eta targeted the Santiago Bernabeu stadium in the buildup to a Champions League semifinal clash between Real Madrid and Barcelona, per the Telegraph.

Westgate Mall in Nairobi, BBC

The latest incident, though, will heighten worries about the security situation in East Africa—a topic high on the agenda following last month's high-profile incident in Nairobi's Westgate Mall.

Sunday's match eventually went ahead without disruption, as Nigeria secured a 2-1 away victory thanks to two goals from Emmanuel Emenike—effectively ending Ethiopia's hopes of a first World Cup qualification.

The game was marred by post-match incidents, however, with BBC Sport reporting that the Nigerian Federation is demanding that FIFA takes action over attacks on the team bus.

Betis midfielder NosaIgiebor was left needing emergency treatment after heavy blood loss from his right palm following the incident.